Whatever happens in the forthcoming European Union referendum, the UK's relationship with the EU is going to change radically over the next few years. If we vote "leave", we can take back control of our future.

If we vote to "remain", then the EU will keep taking more power and money every year as it has for decades. The EU has set in place plans for another Treaty soon after our referendum, which will transfer more power to Brussels. There is no status quo.

The EU is currently extraordinarily expensive for us. The total cost to the UK of our membership is £19.4bn ($29.8bn) a year or over £350m a week. Few people think it is sensible for us to turn away at our borders PhD students from the USA, computer programmers from India and students from China while we have open access to tens of thousands of people with little or no qualifications from Central Europe.

Equally, few people think we get any benefit from being part of either the Common Agricultural or the Common Fisheries Policies, while most people would prefer decisions about our social and employment policies to be taken by our MPs in Westminster rather than by the unelected Commission in Brussels.

Perhaps most important of all, the UK – thank goodness – is not part of the single currency, which is causing such huge problems in the eurozone. If the euro is to survive, however, there is no way in which this can be done – as the EU leadership explicitly recognises – other than for the countries involved moving to banking, monetary, fiscal and then political union.

The UK does not want to be part of a United States of Europe but how are we going to safeguard our position from "ever closer union" if we are the only large country in the EU but outside the euro?

Like many other people, I was hoping these major problems would be tackled during the current process of renegotiation, to produce the kind of relationship with the EU that the vast majority of the UK electorate would like to see. This would be the UK trading freely with the continent and co-operating closely in every way we can, which makes sense – but on an inter-governmental basis rather than within an increasingly centralised political union.

It is because it is becoming increasingly clear that the current negotiations are not going to get us anywhere near this state of affairs that I think the time has come to recognise we would be better to vote to leave the EU, and to renegotiate afresh from the outside over the new arrangements that we really want.

This is why I am now part of the Vote Leave campaign. It is because I don't think radical changes are now going to be achieved that I recognise we have to start preparing now if we are going to fight a successful Leave campaign. We cannot wait until the referendum is about to take place before we begin to get ready for it. There is much too much preparation to be done.

I believe not only that it is in the UK's interest for our relationship with the EU to be re-forged, but it would also be very much to the benefit of the other EU member states for this to happen too. They could then build the United States of Europe that the EU political leadership wants without having us dragging our feet and holding them back.

Mutual free trade is in everyone's interest and it would be to no one's benefit for this to cease. While retaining our national sovereignty, we would make sure the EU would have our full co-operation wherever this was worthwhile.

The tragedy as I see it is that by being so timid in our current renegotiation stance, we are throwing away a huge opportunity, which would benefit everyone. I believe not only that it is in the UK's interest for our relationship with the EU to be re-forged, but it would also be very much to the benefit of the other EU member states for this to happen too.

This is where I think we ought to be and this is why I think we need to seize the opportunity to leave the existing arrangements and negotiate new ones along the lines that would work much better than those we have at present – not only in our interests but also to the long-term benefit of the other EU nation states too.

John Mills is founder of consumer products company JML and a major donor to the Labour Party. He is a board member and the treasurer at Labour Leave. He also runs his own blog.